WHAT IT DOES: Makes hair soft and delivers a glassy, mirror-like sheen

KEY INGREDIENTS: Silicones (shine enhancers)

HOW IT FEELS/SMELLS/LOOKS: A clear liquid with the scent soft, clean-laundry scent

WHY WE LIKE IT: This stuff takes about three minutes to work—just wash it in after you shampoo and condition—and it gives hair a brilliant gleam that lasts for a week. It's basically straight-up silicone, though, so don't use it if you have fine or thinning hair.